You can always go the Ghetto route. Remove all of the speakers and amps (save about 50 lbs or so). Leave the head unit in for looks.
Then buy yourself a nice boom box. One of those big silver bitches that we all used to carry on our shoulders back in the late 1980s. Though, those damn things weigh 20 lbs but you are still 30 lbs less and with a louder system.
Then get yourself Journey "Frontiers", Def Leppard "Hysteria", Prince "Purple Rain", U2 "Joshua Tree", Poison "Look What the Cat Dragged In" and Motley Crue "Shout At The Devil"...
Go to the store and get yourself some stone washed jeans, black Reebok high tops and pull out an old concert t-shirt...
Anyone with a couple old swatches lying around....
Now that is when MTV used to Rock out!!!!
Dave